This invention relates to apparatus and methods for tracking a person""s net calorie intake over a period of time. This invention also relates to apparatus and methods for comparing a person""s net calorie intake to a target net calorie consumption set by the person and warning the person when the target calorie intake is exceeded. The apparatus is provided in the form of a portable wrist-wearable instrument.
There is an increasing awareness that proper nutrition and reasonable amounts of exercise are both very important in the maintenance of good health. In affluent societies people tend to consume more food than is good for them and to exercise too little. More specifically, peoples"" net calorie intake, i. e. calories consumed (typically through food) minus calories expended (typically through exercise), is too high. This contributes to weight increase. A major problem faced by people is that it can be difficult to keep track of net calorie intake, particularly where one has a diet and exercise regimen which fluctuates from day to day.
Setting and observing daily target calorie consumption levels can be useful in maintaining a healthy lifestyle. A person""s target net calorie intake level varies depending on various personal characteristics, such as age and metabolism rate. It also depends on the person""s weight objectives. For example, a person might set a relatively low target net calorie intake if the person wishes to lose weight. The same person might set a higher target net calorie intake if the person desires to maintain a healthy weight.
The patent literature is replete with various devices which are designed to assist a person in keeping a record of the number of calories they have consumed over a period of time. Some of these devices are described, for example, in U.S. Pat. No. 5,033,561 to Hettinger; U.S. Pat. No. 5,233,520 to Kretsh et al.; U.S. Pat. No. 4,686,624 to Blum et al.; Canadian patent No. 1,275,733; U.S. Pat. No. 4,924,389 to Ferry et al.; and U.S. Pat. No. 4,192,000 to Lipsey. A problem with such devices is that they focus solely on the calories consumed by a user. These devices do not encourage a recognition that it is the net calorie intake of a person that is important.
There are also various devices for enabling a person to track the number of calories they have expended through exercise. These include U.S. Pat. No. 5,839,901 to Karkanen; U.S. Pat. No. 4,951,197 to Mellinger; and U.S. Pat. No. 5,704,350 to Willams. Many of these devices suffer from the disadvantage that they rely upon estimates of the type and duration of exercise conducted by the user. Such estimates are often highly inaccurate and typically do not take into account the fitness level of an individual user. Typically these devices require users to tediously manually enter information about the exercises which the user has carried out. Many of these devices are unwieldy and are not practical for a user to keep handy at all times during the day.
There have been some attempts to provide devices which are capable of keeping track of both calories consumed during a given period and calories expended in the same period. For example, German patent application No""s. DE3819248 and DE2949550 describe such devices. Both of these devices rely upon a user entering through a keypad information describing the types and duration of exercises which the user carries out. Only a few broad types of exercise are provided for. Neither of these devices permits reliable measurement of calories expended by a user in exercise during the day.
Segar et al. (U.S. Pat. No. 4,212,079, issued Jul. 8, 1980), discloses a calorie monitoring device which permits users to compare calories consumed with calories expended. The Segar et al. device can sound an alarm every time calories consumed exceed calories expended. Calories expended include an estimate of calories burned by an individual when xe2x80x9cat restxe2x80x9d plus an estimate of calories burned by an individual when exercising. A problem with the Segar et al. device is that its estimates of energy expenditure are derived from information entered by a user regarding the types and durations of exercise. These estimates can be unreliable.
Diaz (U.S. Pat. No. 5,890,128, issued Mar. 30, 1999), discloses a handheld computer containing an extensive list of foods, with their associated caloric and fat contents. The Diaz device also includes a list of exercises, with their associated caloric values, the latter being tailored to the user""s personal characteristics. A problem with this device is that its calorie expenditure calculation is imprecise.
There remains a need for apparatus which can assist users in the maintenance of healthy lifestyles by tracking both the calories consumed and the calories expended by the user and comparing it to a user defined target net calorie consumption. There is also a need for such devices which alert the user when he or she has exceeded their target net calorie consumption. This allows users to modify their behavior. There is a particular need for such devices which accurately estimate the calories expended through exercise. There is a particular need for such apparatus which is small, unobtrusive and convenient to use.
This invention provides a device which tracks both the number of calories consumed by a user and the number of calories expended by the user in exercise and compares the net intake level with a target net calorie consumption. The apparatus is wrist wearable and provides the user with a readily accessible indication of the net intake level with respect to the target net calorie consumption.